3,386 research outputs found

    Evolution and development of staminodes in Paronychia (Caryophyllaceae)

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    Staminodes are infertile stamens that have evolved numerous times in flowering plants and exhibit a vast array of forms and functions. Variation in staminodes suggests that numerous evolutionary processes underlie their origins, but to understand their how and why they evolved, comparative studies are needed in groups of closely related species. Identifying structures as staminodes is not always straightforward and sometimes requires corroborating phylogenetic and developmental evidence. Staminodial structures in Paronychia (Caryophyllaceae), for example, vary in shape and size and have been referred to as both petals and staminodes, rendering their homology uncertain. The development of staminodes was compared across species of Paronychia. We tested the hypotheses that structures were either petals or staminodes and by evaluating floral development of fourteen species with scanning electron and light microscopy and conducted ancestral state estimations across phylogenies to infer when staminodes evolved. Staminodes developed between the stamen whorl and carpel, indicating a true staminodial origin. Staminodes evolved prior to the origin of Paronychia and were lost at least three times. Staminodes in Paronychia began as vestigial stamens following the loss of anthers and were either highly reduced, remained vestigial, or coopted, which we term the vestigial intermediate hypothesis. Our results illustrate a dynamic history of staminodial evolution in Paronychia and that selection on the function of staminodes can differ across closely related species

    George Washington

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    Portrait of George Washington, facing right. Includes facsimile of Washington\u27s signature.https://egrove.olemiss.edu/skipwith/1019/thumbnail.jp

    Protocol for a longitudinal qualitative interview study: maintaining psychological well-being in advanced cancer - what can we learn from patients' and carers' own coping strategies?

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    IntroductionPeople with advanced cancer and their carers experience stress and uncertainty which affects the quality of life and physical and mental health. This study aims to understand how patients and carers recover or maintain psychological well-being by exploring the strategies employed to self-manage stress and uncertainty.Methods and analysisA longitudinal qualitative interview approach with 30 patients with advanced cancer and 30 associated family or informal carers allows the exploration of contexts, mechanisms and outcomes at an individual level. Two interviews, 4–12?weeks apart, will not only enable the exploration of individuals’ evolving coping strategies in response to changing contexts but also how patients’ and carers’ strategies inter-relate. Patient and Carer focus groups will then consider how the findings may be used in developing an intervention. Recruiting through two major tertiary cancer centres in the North West and using deliberately broad and inclusive criteria will enable the sample to capture demographic and experiential breadth.Ethics and disseminationThe research team will draw on their considerable experience to ensure that the study is sensitive to a patient and carer group, which may be considered vulnerable but still values being able to contribute its views. Public and patient involvement (PPI) is integral to the design and is evidenced by: a research advisory group incorporating patient and carers, prestudy consultations with the PPI group at one of the study sites and a user as the named applicant. The study team will use multiple methods to disseminate the findings to clinical, policy and academic audiences. A key element will be engaging health professionals in patient and carer ideas for promoting self-management of psychological well-being. The study has ethical approval from the North West Research Ethics Committee and the appropriate NHS governance clearance.RegistrationNational Institute for Health Research (NIHR) Clinical Studies Portfolio, UK Clinical Research Network (UKCRN) Study number 11725

    Deep Herschel view of obscured star formation in the Bullet cluster

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    We use deep, five band (100–500 μm) data from the Herschel Lensing Survey (HLS) to fully constrain the obscured star formation rate, SFR_(FIR), of galaxies in the Bullet cluster (z = 0.296), and a smaller background system (z = 0.35) in the same field. Herschel detects 23 Bullet cluster members with a total SFRFIR = 144±14 M_☉ yr^(-1). On average, the background system contains brighter far-infrared (FIR) galaxies, with ~50% higher SFRFIR (21 galaxies; 207 ± 9 M_☉ yr^(-1)). SFRs extrapolated from 24 μm flux via recent templates (SFR_(24 µm)) agree well with SFRFIR for ~60% of the cluster galaxies. In the remaining ~40%, SFR24 µm underestimates SFR_(FIR) due to a significant excess in observed S_(100)/S_(24) (rest frame S_(75)/S_(18)) compared to templates of the same FIR luminosity

    Bessie on the Board Walk

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    https://digitalcommons.library.umaine.edu/mmb-vp/4685/thumbnail.jp

    Mapping Global Star Formation in the Interacting Galaxy Pair Arp32

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    A multi-wavelength set of photometric data including UV (GALEX), optical, near-IR, infrared (Spitzer) and radio (VLA 20cm) images and spectroscopic observations are used to map the dust-obscured and unobscured star formation in the galaxy pair Arp 32. The system consists of an actively starforming galaxy and another one with depressed star formation. The most active galaxy has disrupted morphology and different sites of star formation. Spectroscopic data show hints of nuclear activity in its core, intense star formation in limited regions of the galaxy as well as an underlying population of stars witnessing a past episode of star formation. Current star formation rates are estimated from UV and bolometric IR luminosities

    Stellar disks of Collisional Ring Galaxies I. New multiband images, Radial intensity and color profiles, and confrontation with N-body simulations

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    We present new multi-band imaging data in the optical (BVRI and Halpha) and near infrared bands (JHK) of 15 candidate ring galaxies from the sample of Appleton & Marston (1997). We use these data to obtain color composite images, global magnitudes and colors of both the ring galaxy and its companion(s), and radial profiles of intensity and colors. We find that only nine of the observed galaxies have multi-band morphologies expected for the classical collisional scenario of ring formation, indicating the high degree of contamination of the ring galaxy sample by galaxies without a clear ring morphology. The radial intensity profiles, obtained by masking the off-centered nucleus, peak at the position of the ring, with the profiles in the continuum bands broader than that in the Halpha line. The images as well as the radial intensity and color profiles clearly demonstrate the existence of the pre-collisional stellar disk outside the star-forming ring, which is in general bluer than the disk internal to the ring. The stellar disk seems to have retained its size, with the disk outside the ring having a shorter exponential scale length as compared to the values expected in normal spiral galaxies of comparable masses. The rings in our sample of galaxies are found to be located preferentially at around half-way through the stellar disk. The most likely reason for this preference is bias against detecting rings when they are close to the center (they would be confused with the resonant rings), and at the edge of the disk the gas surface density may be below the critical density required for star formation. Most of the observed characteristics point to relatively recent collisions (<80 Myr ago) according to the N-body simulations of Gerber et al. (1996).Comment: To appear in AJ issue of September 2008. High resolution color image of Figure 2 and other supplementary images are available at http://www.inaoep.mx/~ydm/rings

    An algorithmic approach to diagnosing asthma in older patients in general practice

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    The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.WHAT WE NEED TO KNOW: How effective would an algorithm be in helping general practitioners diagnose asthma? What proportion of older people with undiagnosed asthma fail to recognise symptoms? What proportion of the population believe asthma does not occur in the older population? What systems or supports do GPs need to diagnose asthma more effectively? WHAT WE NEED TO DO: Work on developing a gold standard for asthma diagnosis. Develop prototype algorithms for general practice discussion. Conduct a general practice study to assess the effectiveness of an algorithm. In conjunction with GPs, develop a pilot program to increase awareness of the current asthma problem. Conduct focus-group research to identify why some people do not believe they can develop asthma for the first time in adult life. Conduct focus-group research to identify why some adults do not attribute asthma symptoms to asthma. Conduct focus groups with GPs to identify what support is needed to diagnose asthma more effectively. Consult with all stakeholders before an intervention is used. Evaluate any interventions used.Richard E Ruffin, David H Wilson, Sarah L Appleton and Robert J Adam

    Undiagnosed asthma in older people: an underestimated problem

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    The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.WHAT WE NEED TO KNOW: Are older people with respiratory symptoms aware this could be asthma? Which explanations for undiagnosed asthma apply most commonly in older Australians with asthma? Can we improve awareness of asthma in older people with undiagnosed asthma? Is the possibility of asthma in older people firmly established on the general practitioners’ radar screen? What reasons most often determine whether GPs perform spirometry in their practice? WHAT WE NEED TO DO: Conduct a representative population study to assess whether older Australians recognise respiratory symptoms as being asthma and are reporting these symptoms. Conduct and evaluate a pilot asthma health promotion program for older people. Conduct a controlled therapeutic trial of people with undiagnosed asthma to assess treatment benefits and produce treatment recommendations. Identify whether the prominence of asthma in older people can be brought to the attention of GPs. Analyse more carefully the issues associated with innovation of office spirometry.David H Wilson, Sarah L Appleton, Robert J Adams and Richard E Ruffi
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